Free vibratory crusher



United States Patent 3,001,729 FREE VIBRATORY CRUSHER Robert D. Conway, Cedar Rapids, Iowa, assignor to Pettibone Mulliken Corporation, a corporation of Delaware Filed Aug. 19, 1958, Ser. No. 755,972 3 Claims. (Cl. 241-148) One of the oldest machines for crushing rock and the like by power is the jaw crusher. A simple jaw crusher could comprise two jaws, one a fixed jaw which may be called an anvil and the other a jaw which is oscillated by power toward and from the fixed jaw. The jaws are spaced far enough apart at their upper ends so that the rock to be crushed can be fed between them and are progressively closer together downwardly. Near the top, the largest pieces are crushed to somewhat smaller size, and eventually all of the rock fed to the crusher is reduced to a size or sizes fine enough to pass out between the two jaws at the bottom. Hence the spacing between the two jaws at the bottom controls the fineness to which the rock is crushed.

The most common means for oscillating the movable jaw has been by an eccentric bearing on a drive shaft. Such a drive shaft would be journaled in the frame of the crusher and extend outwardly on one side to carry a pulley or the like by which it would be rotated. Within the frame, the shaft is provided with eccentrics, portions ground to cylindrical shape about an axis eccentrio with respect to the axis of the bearings or journals in which the shaft rotates. Bearings surrounding these eccentrics would be linked to the movable jaw so that during each revolution of the shaft and its eccentrics, the jaw would be moved first toward the anvil and then away from it.

According to the present invention, a movable jaw is driven in a free vibratory manner instead of by eccentric bearing means. More specifically, the invention contemplates driving the movable jaw by a balanced pair of rotating unbalanced shafts, all carried by or jointly with the movable jaw. Thus, the drive device is an inertia drive device of a type which has long been used for oscillating heavy equipment, such as horizontal screens and soil compactors.

In spite of the long use of such inertia drive devices for oscillating heavy equipment, it apparently has not occurred to anyone that such a device was suitable for driving the movable jaw of a jaw crusher. If anyone even contemplated such a means for driving a jaw crusher, the idea might have been immediately discarded in the belief that it would not crush rock, or that the movable jaw would quickly push itself away from the proper position with respect to the anvil so that. the spacing would be much greater than intended, and relatively large pieces of rock would fall through.

According to the preferred form of the present invention, twin jaw pairs are provided with the movable jaws of both pairs disposed in back-toward-back relationship and jointly carried by a common carriage. This carriage also carries the inertia driving device. By feeding rock to the passes of both jaw pairs simultaneously, the crushing in each pass prevents the carriage from moving far away from its central position. It appears that as long as the feed to the two passes is nearly equal, the carriage will oscillate about a position centered between the two anvils. Preferably oscillation about this position is ensured by provision of a resilient centering device such as a pair of sturdy springs.

The resulting self-centering tendency is not invincible. One of the advantages of the free vibratory jaw crusher is that there will be less shut-down time due to unbreakable foreign objects entering the crusher. Of course, it

is common to provide some sort of yieldable means for the anvil so that if a piece of iron, for example, enters the crusher pass, the equipment will not be broken but instead the anvil will yield. Often, however, these yield devices are not self-resetting, and some time may be lost from the operation of the crusher. Large unbreakable objects may act in the same way according to the present invention, but smaller ones may merely result in momentary crowding of the carriage toward the opposite side or toward the other anvil. In some situations the presence of such small hard objects in the crusher output would be unobjectionable. In situations Where it is objectionable, a switch device can be arranged to stop the jaw crusher whenever the carriage is thus thrown abnormally off center. Even this may be found preferable to having to reset the yieldable release means of the anvil. In fact, it may make the provision of such a yieldable release means unnecessary, although there has not yet been enough experience with free vibratory crushers to be sure that this will be the case.

Additional objects and advantages of the invention will be apparent from the following description and from the drawings.

Designation of figures FIGURE 1 is a diagrammatic representation of the form of the invention chosen for illustration, FIG. 1 being in the nature of a vertical sectional view in a plane transverse to the jaws.

FIGURE 2 is a vertical sectional view of the apparatus shown in FIG. 1 taken approximately along a plane through the axes of the inertia drive device. 7

General description Although the following disclosure offered for public dissemination is detailed to ensure adequacy and aid understanding, this is not intended to prejudice that purpose of a patent which is to cover each new inventive concept therein no matter how others may later disguise it by variations in form or additions or further improvements. The claims at the end hereof are intended as the chief aid toward this purpose, as it is these that meet the requirement of pointing out the parts, improvements, or

combinations in which the inventive concepts are found.

The illustrated form of the invention includes a main frame 11, a pair of anvils 12 normally having a stationary position in the main frame 11.- A carriage 13 located between the anvils '12 is provided on opposite sides with jaws 14, each of which faces an anvil 12 and an anvil crusher plate 16 forming a part thereof. The carriage 13 includes a pair of opposite side plates 17 by which the carriage is hung. As seen best in FIG. 2, the side plates 17 are pivotably suspended by a cross tube 18, carried by the main frame 11. The pivotal suspension may be through journal type bearings or through rolling type bearings such as roller bearings. Apertures 20 in the side members of main frame 11 receive, and permit oscillation of, projections from the carriage 13.

An eccentric drive devicecarried by the side plates 17 comprises a pair of unbalanced shafts 21 and 22 which are journaled in the side plates 17 by heavy duty roller bearings 23. One of these shafts is driven by a pulley 24 and the second of the shafts is driven by the first shaft through meshing gears 26. The two shafts 21 and 22 are rotated in opposite directions, and the off-center weight portions 27 are in phase with one another and balanced so that when considered jointly they exert no force except in a plane midway between the axes and perpendicular to the plane of the axes. In this thrust plane, they exert very strong forces first in one direction and then in the other, causing the carriage 13 to oscillate about the axis of tube 18.

The central plane about which the carriage 13 oscillates is normally kept in the desired position by sets of centering springs 31 compressed between a depending lug .32 and cross bars 33 extending between and carried by Further details Inertia drive devices of the type indicated are already well known and extensively used, and therefore need not be described in further detail. It may be mentioned that the driven shaft 21 is driven through its pulley 24 by V-belts 25 through a second pulley 41 which rotates about the axis of oscillation of carriage 13. Thus, shaft 42 to which pulleys 41 and 43 are keyed rotates concentrically withtube 18. Belts around pulley 43 may extend to any suitable source of power. Also it may be noted that the off-center or unbalanced shafts 27 will be carried in the housing 46, and that the gears 26'will be housed by a cover 47 and suitably lubricated.

Anvils 12 may be positioned in a suitable manner. They may be pivotally mounted on cross shafts 48, and their lower ends positioned by any suitable jaw opening adjustment device 49. Initially, it is desired that the jaw opening adjustment device 49 be of a type adapted to yield when excessive pressure is applied to the jaw 12. As previously indicated, it is assumed that yieldability of the anvil 12 will be found unnecessary, at least if an automatic device is provided for stopping the drive of shafts 21 and 22 if the carriage 13 moves too far off center. There is in any event relatively little danger of breakage of parts on a free vibrating crusher, since there is no positive forcing of the movable jaw to a given position as is the case with eccentric bearing drive means which has been common heretofore.

Another advantage of the present invention is that the amplitude of oscillation of the movable jaws can be controlled merely by changing the frequency at which the shafts 21 and 22 are driven. With different crushing conditions, different amplitudes of oscillation are preferred. When the amplitude is small, the frequency of oscillation can be higher. With conventional eccentricbearing types of jaw crushers, the amplitude of oscillation is not adjustable, since it depends upon the eccentricity of the eccentric bearings with respect to the shaft bearing.

As illustrated in FIG. 1; it is suflicient protection to have one yieldable anvil 12, the other positioned by an unyieldable stop 51, which may be adjustable by shims 52. An unbreakable piece to the left of carriage 13 will crowd the carriage to the right, the yieldable device 49 yielding if necessary.

I claim:

1. A crusher including an anvil and a crushing jaw having opposed faces converging downwardly to form a 7 crushing pass, the jaw being carried by a carriage oscillatable toward and from the anvil, and means to oscillate the oscillatable jaw including a pair of shafts carried by the carriage to be rotatable about parallel axes in a plane generally parallel to the pass, said shafts being eccentrically weighted, coupled for rotation in opposite directions and being balanced and phased to exert force only in a direction generally perpendicular to the plane to move the jaw toward and from the anvil, and means for driving the shafts including a driven pulley on one shaft, a drive pulley having an axis in said plane, and belt means driven by the drive pulley and driving the driven pulley.

2. A crusher including a pair of anvils horizontally spaced apart, a carriage hanging between them to be generally freely movable toward, one anvil and then away from it toward thev other but biased toward an intermediate. position, jaws carried by the carriage having faces facing the anvils and forming with each a crusher pass, and means to oscillate the carriage including a pair of shafts carried by the carriage to be rotatable about parallel axes in a plane generally parallel to the passes, said shafts being eccentrically weighted, coupled for rotation in opposite directions and being balanced and phased to exert force only in a direction generally perpendicular to the plane to move the jaws toward and from the anvils, and means, for driving the shafts including a driven pulley on one shaft, a drive pulley having an axis in said plane, and belt means driven by the drive pulley and driving the driven pulley.

3. A crusher including a pair of anvils horizontally spaced apart, a carriage hanging between them to be generally freely movable toward one anvil and then away from it toward the other, jaws carried by the carriage having faces facing the anvils and forming with each a' crusher pass, and means to oscillate the carriage including a pair of shafts carried by the carriage to be rotatable about parallel axes in a plane generally parallel to the passes, said shafts being eccentrically weighted, coupled for rotation in opposite directions and being balanced and phased to exert force only in a direction generally perpendicular to the plane to move the jaws toward and from the anvils, and means for driving the shafts including a driven pulley on one shaft, a drive pulley having an axis in said plane, and belt means driven by the drive pulley and driving the driven pulley, and spring means urging the carriage to a neutral position with both jaws spaced from their anvils.

References Cited in the file of this patent UNITED STATES PATENTS 1,491,431 Stebbins Apr. 22, 1924 1,668,984 Simpson a May 8, 1928 1,936,742 Youtsey Nov. 28 1933 2,097,906 Wettlaufer Nov. 2, 1937 2,505,132 Meinhardt Apr. 25, 1950 2,652,985 Linke Sept. 22, 1953 2,766,629 Booth Oct. 16, 1956 FOREIGN PATENTS 581,267 Germany July 24, 1933 727,417 Germany Nov. 3, 1942 878,753 Germany June 5, 1953 

